Imperial Home Page -> Repair -> Frame, Springs and Shocks -> Rust Removal
During the summer of 1999 I began the long task of stripping, priming, and painting the frame. To make light work of this I rented a sandblaster and an air compressor that was powered by a Ford 302 engine. This made rust removal an easy job. I recommend you do this on a warm day when there is no humidity. I found out the hard way that sand clumps together and clogs the sandblaster on humid days. Here is where I also want to take the opportunity to recommend that you take pictures of the entire project.
After I had the frame free of rust, mud, and grease, I began priming it with Corroless Rust Stabilizer from the Eastwood Company. This stuff actually kills the rust and seals the metal from moisture. It can be applied directly over the rust, but I wanted a smooth surface to apply it to. I spent about two days applying this primer. It can be thinned and sprayed, but I opted to brush it on to insure I covered every square inch of the frame.
After the Corroless had dried, I wet sanded the frame with 600, 400, and 240 grit sandpaper. This helped smooth out any brush marks and prepared the frame for a primer surfacer. I used an inexpensive spray can primer to cover the frame. My main concern was just getting the frame smooth and ready for the top coat of gloss black paint. After applying the surfacer I wet sanded the frame again with 400 grit sandpaper.
Finally, it was time to apply the top coat. To finish the frame I used Gloss Chassis Black from the Eastwood Company. It is also available in most original colors, but I wanted my car's frame to be a little more flashy. The frame took me about one month to complete from sandblasting to final painting.
Another way to remove rust from a frame is the easy to use do-it-yourself chemical treatments. Here is what I have learned about chemically derusting and preparing metal for further treatment:
Phosphoric acid: It costs about $2.50 per liter. It can be thinned with water (I really don't know the best ratio, you will have to experiment). It works best unthinned, but then you must keep watching the process as it eats metal. This is called "phosphating". It gives an iron-phosphate coat on the part and, unlike galvanizing, it reaches all holes and crevices. It's a good thing to do to any steel part that will not receive any other treatment before paint or primer. Phosphating will disturb the galvanizing process--it gives marginal corrosion protection compared to galvanizing. A slightly better corrosion protection can be had by using a special phosphoric acid that contains zinc. The process is then called "zinc-phosphating".
If you want to remove the rust, or only clean the parts prior to galvanizing or any other electroplating, use sulphuric acid which does not leave a residue. Both phosphoric acid and sulphuric acid will remove a lot more than a regular solvent you'd use to degrease a part prior to painting. The risk of rust will be reduced by a lot.
Both treatments are very simple to do. Just take a suitable container or bucket, fill it enough so you can emerge the part in the stuff and see how it goes. Both chemicals will not strip paint so you'd need to do that first. Don't put an alloy part in there of course and, needless to say, these are very corrosive chemicals, very nasty stuff. If you have a safe place to keep them you can use them over and over, but I wouldn't know when it's used up. In my humble opinion, phosphating is a lot better than sand blasting. Sand blasting increases the surface area (and thus the risk of rust) by a high percentage and it cannot crawl into a folded seam or weld.
If you're stripping the paint, you must rinse with a lot of water. After that you wash the cleaned frame little dishwashing soap (a little more than you use for dishwashing). Wash the frame again and let it dry. The soap residue is enough to protect against quick rust, and it removes real easy.
And here is a good overview:
Depending on the seriousness and location of the rust, different cleaning methods can be used.
"Dry cleaning" methods include media blasting, wire-brushing, and scraping. We're limiting ourselves to on-vehicle rust here, otherwise sand- or bead-blasting in a blasting cabinet is the hot rust-removal ticket for any parts that'll fit. Alternately, Eastwood offers a Blast Out of a Bucket kit, which includes a compressor-powered blasting gun, a hood and gloves. This method removes rust to bare metal, but sand will find its way into all adjacent areas, so bearings and other moving parts should be taped off. Also, sand particulates can lodge in the lungs and cause silicosis, so a respirator must be worn.
For the average do-it-yourselfer, good ol' elbow grease is the time-proven way to remove rust flakes. Low-tech methods include a standard wire brush, a scraper or a sanding block with coarse-grit paper. Higher up the evolutionary ladder are drill-mounted wheels, brushes and discs. Eastwood offers a variety of these; its 5-inch Cleaning Wheel is a good all-around rust-chaser. The underlying goal is to knock off as many rust flakes and bubbles as possible so that oxygen pockets won't remain under the topcoat.
A variety of rust inhibitors are available in auto parts stores and through mail-order catalogs. Not all of these products are compatible with primers and topcoats, so reading directions is critical. Even easier is to pick one line of products for all pre-paint work.
Working backwards, the final finish determines the metal-prep procedure. Popular finishes include powdercoating, electropainting, rubberized undercoating and painting. Each has its strengths and weaknesses, but the focus here is on on-vehicle rust repair, so painting is the best all-around do-it-yourself solution.
First, rust must be chemically inhibited. Eastwood Metal Wash is one method. It cleans and leaves a rust-resistant coating for situations where prep and priming won't happen on the same day.
For surface rust, particularly in hard-to-reach places, Eastwood offers OxiSolv. This product dissolves iron oxide, replacing it with zinc phosphate. Following a secondary cleaning with Eastwood's PRE Painting Prep cleaner, the area can then be primed before being top-coated.
For frame de-rusting and revival, Eastwood offers pre-packaged Chassis Resto Kits. These kits contain varying quantities of Corroless Rust Stabilizing Coating and Chassis Black paint. Corroless is a one-step rust-stopper and primer. Formulated for offshore oil rigs, Corroless repels surface moisture, stabilizes existing rust with magnetite, then seals out further oxidation with interlocking glass leaves. Since Corroless is UV-resistant, it doesn't need to be top-coated, although it does adhere to most non-lacquer automotive paints.
For a durable, easy-to-apply finish, Eastwood offers Chassis Black paint. The product is available in two sheens: glossy (about 85% gloss) or OEM-look (60-70% gloss). Chassis Black has an epoxy base to help fend off chips and corrosion, it withstands temperatures up to 300 degrees F and is UV-resistant. Chassis Black adheres to bare metal or Corroless but not to self-etching primers.
This page last updated September 17, 2001. Send us your feedback, and come join the Imperial Mailing List - Online Car Club